Thermostatic device



July 7, 1931.v E. A: RUTENBER 1,813,427

THERuosT/,ATIC DEVICE Filed Sept. 18, l926 2 Sheets-Shen l MIT-Inl Julyv 7, 1931.

E. A. RUTENBER 1,813,427

THERMOSTATIG DEVICE Filed Sept. 18, 1926 2 Sheets-Sheet 2 a l@ I O n 1 2 2.3 2 la l 7 f 2| 2 8 LN7 34 l5 Patente-d July 7, 1931 UNITED STATESl PATENT OFFICE y EDWIN A. RUTENBER, OF WISOONSIN, ASSIGNOR TO .L J'. LINDEHANN &

HOVEBSON COMPANY, F MILWAUKEE, WISCONSIN, .A CORPORATION 0l' THEBHOSTATIC DEVICE Application tiled September 18, 1926. Serial No. 136,234.

The improvements relate to thermally operated devic'es for controlling the temperature of ovens and the like, and are primarily intended to be used` in connection with elec- 1 trically heated ovens, but have other applications. Their objects are, among others, to improve the construction and'arrangement of the parts, including the heat responsive member, switch and visible indicator and their connections, rendering the same more eicient, durable and dependable and strengthening and simplifying the construction and the assembling thereof; to protect the parts against accidental injury in use, and to locate them lat such a part of the oven or the-like and arrange them in such a manner that they will be more convenient to the operator and user.

'The improvements are illustrated in the accompanying drawings, in which Fig. 1 is a front view of a corner of an oven frame with thermostatic device embodying the improvements mounted therein;

Fig. 2 is a side view thereof with the protecting cover for the switch and connections zaremoved; v

Fig. 3 isa vertical cross section on the line 3 3 of Fig. 2 looking in the directionindicated by the arrows in that figure;

Fig. 4 is a perspective ofthe case or housing n in which the operating parts are mounted and by which they are protected. V The thermostatie .device or temperature control of the present improvements is designed to'be set in or built into the side of the oven, with theindicator for controlling and indicating the tem rature projecting through the front ame yof the range and covered by a curved plate having therein a window or'sight of transparent 4o material through which the indicator and the scale may be observed. The construction of the operating partstis similar to that shown and described 1n the oo-pendnlzpplication of Lindemann and Ru'tenber, 10, 1924, Serial Number-,7 42,7 48, which shows a tube containing. a globule of conductive mau-tilted therewith.

terial mounted 'on'oie end'of an oscillatory shaft to rock therewith, the 'shaft rotating in a rotatable bearing, to the other end of which lo is attachedthe free end of a spiral or coil f p plate thereof, 3 the top October thermostaticmetal, the opposite end of said.

coil being fastened to the rotatable bearing which has mounted thereon an indicatin lever connected therewith by frictiona means permitting adjustment.4 The said app lication is therefore referred to for illustration and description of details of construction not herein fully set forth.

In the drawings, 1 represents thefront plate of the oven and. range, 2 the outer side plate or cover, and 4 the inner wall of the oven which is spaced from'its outer walls to provide the usual heat insulating chamber ofa double oven. On the front plate is fixed the segmental cover plate 5 with a curved window 6 therein, and having a`chord slot 7 in its side through which the small handle 9 of the indicator projects and in which it moves. The scale 8 is secured to the front ovenl plate `and has numbers and graduations thereon to indicate temperatlres. The scale plate is also substantially on the arc of the indicator, as is also the outer part of the cover 5, the window 6 and slot v7, and this insures accuracy of indication enabling the pointer to pass over the scale in close roximity thereto.

The handle 9 and indicator 10 are fixed to the end of an nular flange 13 on theA sleeve 12 so that the said sleeve can be rotated thereby in its fixed tubular bearing 14 and the thermostatic helical band 15 turned to a limited' extent thereby by reason of the fixed connection 16 between the inner end of said sleeve and the said helical band. thermostatic element ma have the form shown or any other desired orm, and may be made of any material suitable for 'the purpose. f

To the op osite end o the band 15 the inner end of the shaft 17v is fixed, as indicated at 18,

so that when the band turns the shaftis rocked, and the vessel 19 mounted in ixedrelation thereto on lts opposite end, by means of the vmetal strap 20 and clamping nut 21 1s The vessel is of glass or other non-conductive material and has therein a globule 2210i conductive' material normally in one end thereofin contact with the 'terminals 23 mi2-1V of time electric conarm 11 in turn fixed to the an-` ductors 25 and 26 to close the circuit which energizes the'heating unit. When the coil l5 expands under the influence of heat it rotates the shaft 17 counterclockwise (Fig. 2)

seen, therefore, that when the arm 11 is moved upward the bottle is canted to a greater degree, and a greater torsion of theband 15, requiring a greater degree of heat,- will be necessary to rock it to and beyond horizontal position and break the circuit. In order to adjust the instrument to the oven in'connect0n with which it is used so that the readings of the scale will be accurate a toothed disk 27 is mountedy on the shouldered 'end of the sleeve 12, and forms the connection between the annular flange 13, carrying the arm, and the sleeve, the saidfiange being actually an annular ring set on the sleeve. To adj ust the arm 11 therefore with respect to the sleeve it is only necessary to loosen the set screw 28, in fixed relation to the former, thus disconnecting the two and to move the arm to the desiredv extent, then tighten the screw and secure it in position. In this simple manner the instrument may be calibrated when it is assembled and mounted in the oven, or at any other time. It will be understood that the toothed disk or ring 27 is fixed to the sleeve 12.

The housing for the switch, arm and their connections is in the form 29 (Fi 4) with a central opening 30 in which t e tubular housing 14 is threaded, an opening 31 through which the conductor wires may be passed and screw holes 32 and 33 to receive fastenin means whereby it is attached to the outer s1de plate and the front plate respectively ofthe oven. The protecting cage 34 forthe thermostatic coil 15 is threaded on theinner end of this housing. To assemble the instrument, therefore, it is only necessary to pass it through the large opening 2 in'the side late, pass screws through the holes 2l andp through the holes 32 and then place the cage in position from set screws-11. p v. cured'to the front plate and .the curved cover the inside of the oven. This enables the manufacturer to assemble'the instrument before it is applied to the oven.` The arm 11 is passed through the opening 1 in the front plate before the indicator plate and the parts carried thereby are attached, and secured to the extension 13 of the fiange 13 by means of The scale plate y6 is then se- 5 placed ove'r'it, the' slot 7 being paed over the handle 9 in thls operation, and the said cover then secured to the oven front. -The ,switch and said element of a hollow casting secure the housing 29,

the housing because the latter is also secured A to the front plate of the oven. Therefore, the plate 35 may beremoved and replaced, and access to the instrument obtained thereby without disconnecting any other part.

I claim:

1. In combination with a heating chamber having inner and outer walls spaced apart, 'a thermostatic device for controlling thle generation .of heat in said chamber having a temperature responsive element therein and switch and control mechanism mounted between said walls, the outer of said walls having an opening to permit the insertion and removalof said switch mechanism and element, a removable cover for said opening,

a rigid housing supporting said switch, ele-` ment and control positioned between said 2. In a thermostatic temperature control Y device, the combination with a heating lcompartment, of a heat operated element in said compartment, electric conductors .for a current to operate heating means for said compartment, a switch operatively connected with said element and arranged to be operated thereby to interrupt the current passing through said conductors and means for varyling the operative relation between said extending away* from the same to a point exterior to said compartment, a housing within t-he outer walls of said compartment receiving said A,

switch and varying means and fixed means for indicatin the extent of such variation located exteriorA to said compartment, said compartment having multiple walls spaced apart, said switch being located between said walls with said varying means and said indicator means being positioned exterior to said walls.

3. I ncombination with aheating compartment having inner and outer walls spaced apart, a helical thermostatic member dis-- posed in said compartment, a.r rotatable sleeve extending through said inner wal1,-a

rotatable shaft extendin through said inner wall, said sleeve and s aft being connected b said helical member, a circuit maker and reaker within said wallsand supported oli said shaft, an arm for rotating said sleeve 'and disposed between said walls, a

.portion of said arm eXtending-exferiorly of the walls, an indicator scale exterior to said walls with which said arm portion is associated, a disc within said walls fixed to said sleeve, releasable means connecting said disc and arm, and disposedbetweensaid walls, said means4 being releasable for arm relatively to said switch.

4. In ,combination with a heating commoving said v partment having -inner and outer walls spaced apart, a thermostatic member disposed in said compartment, a rotatable sleeve extending through said inner wall, a rotatable sha-ft extending through said inner wall, said .sleeve and shaft being connected by said thermostatic member, a circuit maker and breaker within said walls and supported on said shaft, actuating means including an arm for rotatin said sleeve and disposed between said w ls, a portion of said arm constituting a pointer, an indicator scale with which said arm portion is associated, a disc within said-walls fixed to said sleeve, releasable means connecting said disc and actuating means, and disposed between said walls, said means being releasable for moving said actuating means relatively to v said sleeve. y

Witness my hand this 15th day of September, 1926, at the city of Milwaukee, in the county of Milwaukee, State of Wisconsin.

EDWIN A. RUTENBER. 

